Energy-Efficient House: How to Evaluate Energy Efficiency When Buying a Home in Germany

Understanding the Energieausweis: What You're Actually Looking at

Every property for sale or rent in Germany must come with an energy certificate (Energieausweis). The seller is legally required to show it during viewings and hand it over at signing.

There are two types, and the difference matters more than most buyers realize.

Verbrauchsausweis vs. Bedarfsausweis: Which One Can You Trust?

The consumption-based certificate (Verbrauchsausweis) is calculated from the actual energy bills of the last three years, which means it reflects the previous owner's habits as much as the building itself. The standardized-demand-based certificate (Bedarfsausweis) is calculated from the building's technical data, insulation, heating system, and windows, using standardized assumptions about how the building is used. A Verbrauchsausweis can make a poorly insulated house look efficient if the previous owner barely heated it, or make an efficient house look worse if they kept it warm year-round. For comparing properties, the Bedarfsausweis is the more reliable reference.

Under German energy law (§ 80 of the Gebäudeenergiegesetz - GEG), older, unrenovated residential buildings with up to four units whose building application predates November 1, 1977, must use a Bedarfsausweis. Newer or renovated buildings can typically choose either. 

Both certificate types are valid for 10 years from the issue date. Check the issue date before relying on the numbers; an older certificate may not reflect renovations made since.

Reading the Energy Class: What A-H Actually Mean

Since May 2014, every Energieausweis includes an energy efficiency class, from A+ (most efficient) to H (least efficient), shown on a colour scale similar to appliance labels.

The class is based on final energy demand or consumption per square meter per year (kWh/m²·a). A class A house uses roughly 30-50 kWh/m²·a. A class H house can use over 250 kWh/m²·a, five times as much for the same living space.

A lower class isn't automatically a dealbreaker. It's a starting point for negotiating price, planning renovation costs, or budgeting for higher running costs.

Apartment vs. House Energy Class: Electricity vs. Gas Costs 

The energy class translates directly into what you'll pay to heat the property. The section below breaks down estimated annual heating costs for both a 70 m² apartment (the average size for German urban properties) and a 100 m² single-family house, based on national average gas and electricity prices.

If your property is a different size, you can easily calculate the estimated cost using this formula:

Annual Heating Cost (€) = Property Size (m²) × Standardized Energy Demand (kWh/m²·a) × Energy Price (€/kWh)

Single-Family House: Energy and Electricity Breakdown by Class

_{Source: Energy demand classes defined under GEG Anlage 10. Estimated energy costs calculated using national average household tariffs from Destatis and the Bundesnetzagentur. *Note: Demand figures and cost calculations apply strictly to heating and hot water production, excluding general household electricity (appliances, lighting, etc.). Electricity estimates reflect dedicated heating tariffs (Heizstrom) or heat pump operation.}

Apartment (ETW): Efficiency Classes & Heat Systems Impact

_{Source: Energy demand classes defined under GEG Anlage 10. Estimated energy costs calculated using national average household tariffs from Destatis and the Bundesnetzagentur. *Note: Demand figures and cost calculations apply strictly to heating and hot water production, excluding general household electricity (appliances, lighting, etc.). Electricity estimates reflect dedicated heating tariffs (Heizstrom) or heat pump operation.}

Example. A 70 m² apartment in class G heated with gas costs roughly 2100€ per year, compared to just 420€ for a class A apartment of the same size, saving 1680€ annually. For a 100 m² house, that difference jumps to 2400€ every year.

What Does an Efficiency Value of 70 or 80 Mean?

You'll also see references to KfW's Effizienzhaus standard, labeled with numbers like 40, 55, 70, or 85. This number represents the property's primary energy demand (Primärenergiebedarf) as a percentage of a reference new-build. An Effizienzhaus 70 uses 70% of the energy a standard reference building would use, so a lower number means better performance (you can see how these standards map directly to energy classes A+ through B in the overview table above).

This standard matters mainly for new builds and major renovations, since it also determines eligibility for KfW subsidized financing.

How to Check the Energieausweis Before You Buy

Before making an offer, ask the seller or agent for:

For older houses in particular, a Bedarfsausweis gives you a more honest baseline than a Verbrauchsausweis inflated or deflated by a previous owner's habits. If the seller only has a Verbrauchsausweis for an older, unrenovated property, it's worth asking why, since a Bedarfsausweis may be the legally required option in that case.

Impact on Financing: Interest Rates and KfW Funding

Energy efficiency doesn't only affect your utility bills. It affects your mortgage too. Lenders in Germany often offer better interest rates for energy-efficient properties, and government-backed KfW loans can reduce your financing costs further if the property meets specific efficiency standards.

The bottom line: Better energy classes can unlock lower mortgage rates (green discounts) and low-interest subsidized loans, significantly lowering your overall monthly payment. 

For financing details, dedicated guides go deeper into each program:

GEG Legal Requirements for Energy Efficiency

When you buy a home in Germany, the law requires you to complete certain energy upgrades within two years of taking ownership. These rules are part of Germany's Building Energy Act (Gebäudeenergiegesetz – GEG, updated under the GModG in July 2026).

If you buy an older, unrenovated property, your mandatory post-purchase tasks (Nachrüstpflichten) usually include:

What about old boilers? The old rule requiring buyers to automatically replace 30-year-old gas or oil boilers (§ 72 GEG) was officially removed in the July 2026 legal update. Today, an older boiler can stay as long as it works safely and passes chimney sweep inspections, though replacing it voluntarily can unlock substantial government subsidies.

On the other hand, lenders check for these mandatory upgrades during your application. Since skipping them can result in fines, banks want to see that you have a plan and enough budget to complete the work. Fortunately, banks can usually include these renovation costs directly in your mortgage loan.

So you need to ask the real estate agent if such mandatory upgrades are needed, especially for properties that have lower energy-efficiency ratings.

Apartments: Evaluating and Improving Efficiency with a WEG

If you're buying an apartment rather than a house, the Energieausweis still applies, but your ability to act on it is different. Structural changes, like replacing windows or insulating the building's exterior, require approval from the owners' association (Wohnungseigentümergemeinschaft, WEG), not just your own decision.

Before buying, ask about the building's overall energy class, not just the unit's, and check whether any renovation is already planned or under discussion at WEG meetings. These decisions can significantly affect your future costs, either through better efficiency or a special renovation levy (Sonderumlage).

Is it Worth Improving Efficiency? Typical Modernization Costs

If you are considering buying a less efficient property to renovate, exact costs depend on its size, age, and condition. According to consumer organization benchmarks (Verbraucherzentrale), typical upgrade costs range as follows:

Exact costs depend heavily on the property's size, age, and the contractor, so treat these as a starting point for budgeting, not a fixed quote.

Also, keep in mind that Federal government programs (like BAFA) offer subsidies covering up to 15%-20% of individual energy efficiency measures, significantly lowering out-of-pocket costs.

How to Improve Energy Rating: Heat Pump Subsidies

Upgrading an outdated heating system to a modern heat pump (Wärmepumpe) is one of the most direct ways to boost a property's energy class, reduce running costs, and secure long-term value.

Through the Federal Incentive for Efficient Buildings (BEG), heating modernizations in existing properties receive substantial financial backing via direct KfW 458 grants combined with low-interest KfW 358/359 supplementary loans:

1. Direct Heating Subsidies (KfW Grant 458)

Owner-occupiers upgrading their heating system can combine several subsidy bonuses:

Subsidy Cap: Although combining these bonuses can theoretically exceed 80%, total direct subsidy payouts are capped at 70% of eligible investment costs (with eligible expenses capped at 30.000€ for a single-family home or the first residential unit).

2. Subsidized Supplementary Financing (KfW 358 / 359)

To cover the remaining out-of-pocket costs after receiving grant approval from KfW 458 or BAFA, buyers can access dedicated supplementary loans (Ergänzungskredit):

Loan Limits: Up to 120.000€ per housing unit in flexible financing, allowing buyers to conveniently combine grant payouts with structured long-term capital through their main mortgage provider.

Buy vs. Renovate: Which Makes More Financial Sense?

Deciding between a move-in-ready property (Energy Class A/B) and an inefficient fix-up (Energy Class F/G) comes down to three measurable financial metrics:

So, buying to renovate makes financial sense if the purchase price discount plus state subsidies fully cover initial upgrade expenses, resulting in lower monthly carrying costs and long-term asset protection.

FAQ

Which Type of Energieausweis is Mandatory for Old Houses?

Older, unrenovated buildings with up to four residential units built before November 1, 1977 are generally required to use a Bedarfsausweis rather than a Verbrauchsausweis.

How Much Does an Energieausweis (EPC) Cost in Germany?

Costs depend on the type of certificate:

Remember that as a buyer, you do not pay for this; the seller or landlord is legally required to provide it free of charge.

Is a House With Energy Class H Good or Bad?

Class H is the least efficient rating on the scale, meaning significantly higher energy demand than average. It's not automatically a dealbreaker, but it should factor into your price negotiation and renovation budget.

Which Energy Class is Better, A or E?

A is more efficient than E. The scale runs from A+ (best) to H (worst), based on energy demand per square meter per year.

How Long is an Energieausweis Valid?

Both certificate types are valid for 10 years from their issue date.

Who Can Issue an Energieausweis?

Qualified professionals such as certified energy consultants (Energieberater), architects, or engineers with the relevant training can issue either certificate type.

Summary: Next Steps for Buyers Evaluating an Energy-Efficient House

The Energieausweis is more than a formality. It tells you what you'll actually pay to heat a property, what a bank may offer you in financing, and whether the property already meets Germany's legal requirements. Before you make an offer, check the certificate type, its issue date, and the underlying numbers, not just the letter grade.

Ready to see how a property's energy class affects your specific financing options? Book a free consultation with a Hypofriend advisor.